Problem: Solve for $y$ : $y + 1 = 12$
Solution: Subtract $1$ from both sides: $ \begin{eqnarray} \\ y + 1 &=& 12 \\ \\ {-1} && {-1} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{1 + y} &\hphantom{=}& \hphantom{12} \\ y &=& 12 {- 1} \\ \end{eqnarray} $ Simplify. $ y = 11$